Subject: [CCAMP] An unresolved discussion on FlexE at IETF meeting.

From: [email-masked]
Date: Fri, 15 Apr 2016 15:03:38 +0800

Hi Fatai, CCAMPers,

"FlexE only provides interfaces. It does not provide networking, which 
means that FlexE cannot support swithching. So, from the control plane 
perspective, we only care about adaptation. "

Thanks for your comments at the IETF meeting.

Based on your feedback, I think I agree with part of your opinion. I 
should admit that FlexE do not support switching, because there is no slot 
switching in FlexE, but I don't think FlexE can not provide networking. 
Maybe because I have different understanding of "networking" here. I use 
an example to describe my understanding.

In the case depicted in the following figure, B and E are FlexE capable 
nodes, C and D are traditional OTN ODUflex/ODU4 capable nodes. There are 
three available Ethernet PHYs between node B and C, node D and node E. 
First, suppose node B receives a FlexE client path set up request from 
node B to node E and the bandwidth of this path is 150G. 
Second, given any single link between node B and node C, node D and node E 
can not be used to carry traffic larger than 100G, node B decides to use 
FlexE to carry traffic towards node E through the bonding of Ethernet 
PHYs.
Third, the FlexE signaling process assigns FlexE group number, dynamic PHY 
number for the PHYs to be used and slots information for the client.

I think all the thing done in this process is networking.

                     +---+                      +---+
                     | B |                      | E |
                     +---+                      +---+
                         \                     /
                          \                   /
                          +---+          +---+
                          | C |----------| D |
                          +---+          +---+

I think we need some discussion here. Because I think there should be such 
a FlexE control plane technology to help set up end-to-end FlexE 
connection to carry traffic larger than that can be carried by a single 
Ethernet PHY.

Thanks
Qilei